Hey guys,

Has anyone had any experience with torque-to-yeild (TTY) head bolts?
I'm getting ready to replace the head gaskets on a 1996 Mustang with a 97 3.8 V6.
I will be using new head bolts, but the tightening procedure is very weird.
There's 6 steps involved ...
Step 1. torque to 15 ft. lbs
Step 2. torque to 29 ft. lbs.
Step 3. torque to 36 ft lbs
Step 4. (This is where it gets weird) Loosen 2 or 3 turns (DO NOT loosen all the bolts at once, from here on do this step and the next ONE BOLT AT A TIME.
(Why loosen a bolt that's already been tightened?)
Step 5. long bolts 29-37 ft. lbs. short bolts 11-18 ft. lbs.
Step 6. Tighten an additional 180 degrees
What's the point of this?
Could I just get some non-TTY bolts from ARP and tighten the bolts to 65 ft. lbs and say the hell with it?

Thanks,

Brian

 

Where the %&$##$% are you getting this less than stellar info from ?
You never loosen a torqued head bolt and retighten.
Once you crush the head gasket ,the last thing you want to do is take pressure off it.

 

yes actually u are supposed to loosen up the bolt, but just a little bit, not much, it helps stretch the threads.

 

I got this less than stellar info from a repair manual. Seems crazy doesn't it?

 

mitchell says the same thing...def get an angle gauge, i would stick with the tty bolts...there has to be a reason why they used them from the factory.

 

The process seats the gasket, then torques the bolts to their yield.

What if the TTY bolts are why the 3.8's are known to have head gasket issues?

I would run ARP's if you can get them. They are made with superior methods and technology.

 

Yeah, that's a good question. There has to be some explanation for the 3.8 head gasket failing so much. The gaskets failed a lot on the Windstars and the 94-96 Mustangs. I sure hope I can find some ARP head bolts.

 

i got mine from advance, took a day or two to come in...


edit: I believe it was just a cheaply made gasket...

 

That's what I was thinking when I read this..however it is what Ford has to say.

 

True

 

The reason FORD and every other company uses them, is to save money. NOT because they are the best quality.

 

Agreed! The factory head bolts are definitely the issue behind their gasket failure. ARP is the best quality for sure, but unfortunately they don't have head bolts. Morana does carry ARP head studs.

 

Actually TTY bolts are better for high load with repeated changing of the load, load frequency.

Head bolts are in that category, repeated heating and cooling of an engine will cause standard bolts to get fatigued from the stretching and fail.
If you are old enough you know that happened, and when reinstalling the old ones you would often get one that breaks on final torque........so head has to come off to remove the broken bolt.

Downside of TTY is that you should replace the bolts after removing, upside is that how often to you need to remove heads on an engine.

If you are involved in racing then use studs, if you have the clearance to remove heads, because you will be pulling the heads more than on a Daily Driver.

If not then just replace the TTYs with new TTYs, new standard bolts will cost the same if not more and if you do it right heads won't need to come off for a long long while.
Moot point IMO

 

True just look at the 6.0 powerstroke